Police in South Korea have raided Google's Seoul headquarters as part of an investigation into data collected by the company's Street View cars.

Police official Ahn Chang-soo said computers and hard drives had been seized in the raid by 19 Korean National Police Agency (KNPA) officers on the Google premises in the South Korean capital.

"[The police] have been investigating Google Korea on suspicion of unauthorised collection and storage of data on unspecified internet users from Wi-Fi networks," a statement released by the KNPA added.

A Google spokeswoman said: "We can confirm that the police have visited Google Korea in conjunction with their investigation around data collection by Street View cars. We will cooperate with the investigation and answer any questions they have."

South Korea is one of many countries – including the UK – investigating the data collected by Google's Street View cars. The search giant has admitted to accidentally intercepting fragments – amounting to 600MB – of personal data through Wi-Fi networks in more than 30 countries as it sought to map towns and cities.

In May this year, Alan Eustace, a senior vice president in engineering and research at Google, wrote on the company's blog: "It is now clear that we have been mistakenly collecting samples of payload data from open Wi-Fi networks, even though we never used that data in any Google products."

In June, the company said it had deleted private wireless data collected in Austria, Denmark and Ireland.

A string of code in the production systems of Street View cars allowed Google to retrieve and store information about the networks' location, names and Media Access Control (MAC) addresses on wireless networks that were not password protected.

Last month the UK information commissioner ruled that Google is unlikely to have collected "significant amounts of personal data" with its Street View mapping cars, saying there is "no evidence as yet that the data captured by Google has caused or could cause any individual detriment".

Figures collated and published earlier this year by analysts Aqute Intelligence showed that nearly half of the 60 worldwide legal or criminal investigations being faced by Google relate to the company's Street View service.